The present invention relates generally to vibrating a patient""s lungs to reduce the viscosity of mucus contained therein. More particularly, the present invention relates to a device and method for vibrating a patient""s lungs with low-frequency audio shockwaves.
The human lungs comprise a natural means for clearing mucus. Human lungs contain tiny clearing cilia that vibrate at approximately 18 Hz. At that frequency, mucus has a significant phase change from a viscous to fluid to thinner secretions. Accordingly, the cilia operate to loosen the mucus by making it more fluid. Once the mucus is more fluid, it can be more easily expelled.
Some patients with weak lungs, disease, or other ailments have lungs that cannot create a sufficient phase change in the viscous mucus. Additionally, a doctor may need to induce a sputum sample from a patient. Accordingly, an artificial means of vibrating the lungs at approximately 18 Hz can be used to supplement the patient""s natural mucus system. In some cases, an artificial means of vibrating the lungs can produce the same phase change in mucus as produced by the lungs"" natural cilia.
One conventional method for artificially vibrating a patient""s lungs is by using pulses of air pressure introduced through the mouth and into the lungs. However, such a method can produce dangerously high air pressures, which can damage the fragile air sacs in the lungs.
Another conventional method for artificially vibrating a patient""s lungs is by using low frequency audio of approximately 18 Hz to make lung secretions thinner. Low frequency audio does not induce potentially dangerous high air pressures in the lungs that are associated with the air pulses discussed above. However, conventional methods require very high audio power to cause vibration at low frequencies. Common loudspeaker components can be used to provide a high-powered audio source for vibrating the lungs. However, the life expectancy of the high-powered audio drivers is low, and the cost of the high-powered audio drivers is high. Additionally, powered subwoofers and loudspeakers typically are not disposable or portable.
A patient""s lungs and vocal cords make a particularly efficient loudspeaker in the vocal range. However, low frequencies are not efficiently produced because both the vocal cords and the lungs are too small. If the lungs could be made larger, they would support low frequency audio production, and they also would couple efficiently to a low frequency audio source.
Therefore, a need in the art exists for a system and method that can provide a low-cost, disposable, and/or portable, artificial means of vibrating a patient""s lungs to cause a viscous change in mucus contained therein. A need in the art also exists for an efficient means of coupling a patient""s lungs with an audio source to produce a low frequency vibration in the lungs. Additionally, there exists a need in the art for a non-powered, low-frequency audio source for artificially vibrating a patient""s lungs.
The present invention can provide a device and method for artificially vibrating a patient""s lungs to cause a viscosity change in mucus contained therein. The device and method can be used to clean mucus from the lungs or to induce a sputum sample for diagnostic purposes from the lungs.
The lung vibrating device and method according to the present invention can allow the lungs to produce low frequency audio that can vibrate the lungs at the desired frequency to change the viscosity of mucus. Typically, human lungs are too small to produce low-frequency audio sound. The lung vibrating device and method according to the present invention can comprise an acoustical resistance that can increase the apparent volume of the lungs, thereby allowing the lungs to produce low-frequency audio in the desired range. The acoustical resistance can allow the lungs to couple efficiently to an audio source to produce low-frequency shockwaves. The acoustical resistance can make the audio source behave as if it is operating in a much larger volume than the body cavity alone, thereby allowing low-frequency audio to be produced and considerably improving energy transfer efficiency. The present invention can generate relatively low frequencies efficiently by using an acoustical coupling technique based on Thiele-Small loudspeaker parameters.
The device according to the present invention can use the acoustical resistance to improve the transfer of audio energy to a body cavity such as the lungs. The device can produce low frequency audio and then can use the body cavity as a loudspeaker enclosure. The acoustical resistance can couple the body cavity efficiently to the low frequency sound. Additionally, the acoustical resistance can efficiently couple the sound/audio/shockwave to the body cavity to vibrate the lungs at the desired frequency. Accordingly, small and inexpensive sound sources can efficiently generate low frequency audio in body cavities.
In an exemplary aspect of the present invention, a lung vibrating device can comprise a reed disposed in a housing. A patient can blow air through the housing, which can cause the reed to vibrate and produce an audio shockwave. An acoustical resistance of the device can couple the audio shockwave produce by the reed with the lungs to produce low-frequency vibrations. Accordingly, the acoustical resistance can provide a back pressure that can transmit the low-frequency vibrations into the lungs to cause a viscosity change in mucus.